getListContentForData function added to lists helper. It allows to manually set a list of entities which is to be displayed on the view. Previously, the only function was getListContent, but it retrived data on its own by a single query. The new function can be useful whenever it is impossible or very awkward to obtain entities in such a way (for example more sophisticated SQL statements). Additionally, the getListContent function is reconstructed so that it collects the data first and then calls getListContentForData.

"""
Extracts the version of the PostgreSQL server.
"""

import re

VERSION_RE = re.compile(r'PostgreSQL (\d+)\.(\d+)\.')

def get_version(cursor):
    """
    Returns a tuple representing the major and minor version number of the
    server. For example, (7, 4) or (8, 3).
    """
    cursor.execute("SELECT version()")
    version = cursor.fetchone()[0]
    major, minor = VERSION_RE.search(version).groups()
    return int(major), int(minor)